Frequently asked questions about Ducati Desmoquatro rocker arms.
Q. What is the actual cause of rocker arm failure?
A. The most common failure "Flaking" ("Peeling") is caused by cracking and separation of the hard plated surface from the base material. The stock arms are cast from metal that is plated in the areas that are contacted by the cam shaft. The plating is a very hard and abrasion resistant material but it is also very brittle. The cast metal is porous, nodular, and relatively soft in comparison to the plating. Under normal operating conditions the cam shaft not only slides over the rocker arms it also impacts the face of the arms on each revolution. The plating is well suited to provide abrasion resistance from the sliding action but due to its brittle nature can not withstand impacts. The cam shaft impacting the surface of the rocker arm causes the plating to indent into the the cast metal material below and fracture. The fractured plating then peals off of the cast metal. The cam shaft lobes are then damaged by contact with the abrasive cast material.
Q. Why does your product work where the stock and refurbished rockers fail?
A. The Electraeon Super Rocker Arm design takes into account the actual cause of failure of the stock arms: impact of the cam shaft on the rocker arm. By using a solid impact resistant material that is hardened all the way through the part we have the complete solution: impact and abrasion resistance.
Q. Do I have to remove the cams to see if the stock rocker arms are bad?
A. No. You can see the opening rocker arms by rotating the cam shaft to the position that the cam begins opening the valve. The area of the opening rocker arm that is contacted by the cam shaft will be clearly visible. The closers are difficult to see but may be viewed with the use of a small inspection mirror and bright light or boroscope. Damage to cam shaft lobes is clearly visible by rotating them. All of the above cam be done with timing belts on by rotating the rear wheel with the transmission in top gear when the bike is on a paddock stand.
Q. Can I return to the factory service schedule intervals (10,000km/6000 miles) when using Super Rocker Arms?
Note about the question: Many owners running stock rocker arms accelerate the valve clearance inspection intervals to identify failing rocker arms before they fail completely.
A. Yes, you can. The Super Rocker Arms don't fail so there is no need for frequent checks. Also, we have observed that if the valve clearances are set correctly at installation of the Super Rockers subsequent Valve Clearance Inspections do not require Valve Clearance Adjustments. A Valve Clearance Inspection without changing shims is much easier and faster to perform. The time and expense saved will offset the cost of the Super Rocker Arms.
Q. What valve clearance specifications should I use?
A. Use the factory suggested settings for installation and service limits for your motor. We have heard that some folks have invented new clearance specs. We don't know why or how they calculated them and we don't recommend that you use them.
Q. Is crankcase oil a factor in stock rocker arm failure?
A. No, it is not. Use the type and quantity of oil specified by Ducati for your bike.
Q. Do rocker arms fail on the vertical head more than the horizontal head?
A. They all fail, intake, exhaust, openers, closers, and on both heads. A new stock opening rocker arm we tested failed in 400 miles in the right side exhaust of the horizontal head.
Q. Is incorrect valve clearance settings a possible cause of rocker arm failures?
A. They are going to fail regardless of the valve clearance settings but incorrectly set clearances will do it faster, possibly in minutes. If a zero clearance condition occurs both cam lobes will be pinched against the rocker arms. That's a spectacular amount of wear on both rockers and the cam. Broken split rings that have turned sideways between the opening and closing shims is another cause of zero clearance conditions. We believe that broken split rings can be caused by loose closer settings. It is critical that the clearances be set correctly.
Q. Can I run "G Cams" with Super Rocker Arms?
A. Yes, you can use any of the commonly available Ducati cams. We made the Super Rockers with extra clearance so that can even be used with radical custom made cams. Please contact us for special instructions if you are planing to use a custom made cam.
Q. Do Super Rocker Arms wear the cams?
A. No, they don't.
Q. My cam shaft was damaged by bad stock rockers, what can I do?
A. If your cams are damaged you should replace them before installing new rockers. It may be possible in some cases to repair the cam to a useable condition by very carefully sanding and buffing the damaged area of the cam lobe.
Q. I have a 748R, It revs fast are Super Rocker Arms going to hold up?
A. Spin the motor as fast as you want, use any cam you want, the Super Rocker Arms have held up in every case. You can put them in an SPS or race motors as well. Track days and racing are encouraged.
Q. Is there any performance difference between stock and Super Rocker Arms?
A. There is no measurable difference in performance.
Q. Why do "resurfaced" rocker arms fail?
A. There are a lot of technical challenges when welding on cast iron. Cast iron that is arc welded will have high internal stresses in the metals structure that causes the material to be brittle. Careful preheating before welding and controlling the rate of cooling, or heat treat stress relieving after welding may eliminate the stresses. One problem is that it is very difficult to know if the process has been performed correctly because stresses and resulting cracks may not be visible. The pre-heat, welding, grinding, and stress relieving processes may appear to go well but when the part is put under a heavy load a catastrophic failure may occur. Failures of resurfaced rocker arms that we have heard about include the welded section separating from the base material and the rocker arm breaking in half. There are so many potential problems that welding a highly stressed critical component made of cast iron is considered by many to be bad engineering practice.
Q. Could a bad stock rocker arm damage the rest of the motor?
A. Distributing hard plated material through the motor can damage bearings, cylinder walls and transmission components to name a few. The hope is that the screen filter or oil filter will capture the material before damage is done.
Q. Used rocker arms are cheep why not keep replacing them?
A. Most of the used rocker arms we've seen for sale are already 3/4 shot. Replacing a broken part with a part will fail soon doesn't make much sense. Consider the time and expense of continually replacing rocker arms and possibly the cam shafts. It will be lower cost in the long run to do the job right the first time.
